Coating solutions for forming transparent conductive ceramic coatings, substrates coated with transparent conductive ceramic coatings and process for preparing same, and uses of substrates coated with transparent conductive ceramic coatings

ABSTRACT

In accordance with the present invention, there are provided coating solutions for forming transparent conductive ceramic coatings, said coating solutions being homogeneous solutions or dispersions of acetylacetonate chelate compound, conductive substances and, if necessary, silicon compound and/or alkoxides of metals other than silicon in mixtures of water and organic solvents, and substrates having thereon transparent conductive ceramic coatings formed from said coating solutions and uses thereof.

FIELD OF THE INVENTION

This invention relates to coating solutions (coating liquids) forforming transparent conductive ceramic coatings and process forpreparing the same. The invention also relates to substrates coated withtransparent conductive ceramic coatings, process for preparing the sameand uses thereof. More particularly, the invention relates to coatingsolutions capable of forming continuously at low temperatures such asabout 120° C. conductive ceramic coatings which are extremelytransparent, excellent in adhesion to the surface of substrates such asglass, plastic and the like materials, high in durability such as alkaliresistance, acid resistance and resistance to saline solutions, and inresistance to scuffing.

The invention further relates to substrates coated with transparentconductive ceramic coatings formed by using the above-mentioned coatingsolutions for forming transparent conductive ceramic coatings, and toprocesses for preparing the same. Furthermore, the invention relates todisplaying devices equipped with the above-mentioned substrates coatedwith transparent conductive ceramic coatings as face-plates and copymachines equipped with the above-mentioned substrates coated withtransparent conductive ceramic coatings as platen glass.

BACKGROUND OF THE INVENTION

Glass or plastic substrates are transparent and have a wide variety ofuses. However, these substrates are liable to generate staticelectricity on their surface, because they are insulators. When glass orplastic substrates are used, as they are, as face-plates for displayingdevices such as cathode ray tube (CRT), fluorescent indication pipe(FIP), plasma display (PDP), liquid crystal display (LCD), etc., rubbishor dust attaches to the surface of face-plates and the images displayedare difficult to look at. In the case of LCD, moreover, there issometimes brought about destruction of IC or mistake in display bystatic electricity generated. In a copy machine 1 equipped with anautomatic document feeder (ADF) 2 as shown in FIG. 1, paper clogging issometimes caused by static electricity generated on a platen glass 3 inthe course of feeding documents, whereby continuous feeding of thedocuments can be made no longer. In the case of plastic substrates,moreover, because of their low surface hardness, the plastic substratesreadily receive scuff marks, whereby they sometimes decrease intransparency.

With the view of solving such problems as mentioned above, there areproposed processes for forming on substrates metallic coatings orconductive inorganic oxide coatings by the vapor phase method such asCVD, PVD or sputtering. The coatings obtained by these processes,however, are low in acid resistance as well as in alkali resistance, andliable to scuffing as they are low in resistance to scuffing, thoughthey are excellent in transparency or conductivity. In forming thesesubstrates, it is necessary to use vacuum metallizers and, moreover,there is a limit to an area or shape of the substrate on which thecoating can be formed by the vacuum metallizers. Furthermore, in theseprocesses no coatings are formed at low temperatures, and continuousproductivity is poor because said processes are carried out batchwise.

In the platen glass coated with such an antistatic coating as mentionedabove, the coating formed on the platen glass was sometimes scraped offby the documents fed to ADF or a rubber belt fitted to ADF. When copyingis carried out in higher copy sensitivity, that is, at a gray scale, byusing a copy machine with such a platen glass as mentioned above, therewas brought about such a new problem that the scraped portion areprinted as stains on the copy.

There is also proposed a process for imparting conductivity tosubstrates by coating the substrates with conductive paints prepared bydispersing conductive substances in resin. The coatings obtained by thisprocess, however, had such problems that they are poor in transparency,durability and resistance to scuffing, though they are excellent inconductivity.

The face-plates of displaying devices, on one hand, are requiredsometimes to have a regular reflection reducing effect (hereinaftercalled anti-glare) for inhibiting glaring of the face-plates, inaddition to the antistatic effect thereof. The following are known asprocedures intending to impart anti-glare and antistatic effect to theface-plate of displaying devices. That is, Japanese Patent L-O-P Publn.No. 16452/1986 discloses a process which comprises preheating aface-plate composed of glass or plastics, spraying over said face-platea colloidal solution of a silicon compound such as a partiallyhydrolyzed silicic ester or the like, a silicon compound such as silicontetrachloride or the like, or a solution obtained by mixing saidcolloidal solution with a water-soluble compound of inorganic metal suchas platinum, gold, palladium or tin, and forming a finely uneven coatingcomposed of silicon oxide or its hydrate on the surface of theface-plate, followed by drying and heating.

Further, Japanese Utility Model L-O-P Publn. No. 168951/1984 discloses aprocess which comprises forming a coating layer on the face-plate by thevacuum deposition or dip method from a mixture of tin oxide or indiumoxide and silicon oxide or from a laminate thereof.

In the face-plates obtained by these processes mentioned above, however,anti-glare is insufficient or the antistatic effect thereof variesdepending upon the ambient temperature or humidity. Under certaincircumstances, moreover, resolving power of the displaying devicesequipped with such face-plates sometimes decreased. Furthermore, thecoatings formed on the face-plates are poor in adhesion to theface-plates and easily peel off, liable to scuffing because of their lowresistance to scuffing, and peel off or flow because of their lowdurability, whereby anti-glare and the antistatic effect could not bemaintained for a long period of time.

By way of Japanese Patent Appln. No. 299686/1986, the present applicantapplied for a patent a coating solution for forming a conductivecoating, said coating solution being a homogeneous dispersion comprisingwater and an organic solvent of zirconium oxysalt, silicon alkoxide orits derivative and a conductive substance. The conductive coatingobtained by heating a wet coating formed by using the above-mentionedcoating solution at a temperature of at least 250° C. is excellent inperformance characteristics such as transparency, conductivity andresistance to scuffing. However, the conductive coating obtainedlikewise but by heating at a temperature below 250° C. is poor indurability, and it was difficult to apply said conductive coating to aplastic substrate. Furthermore, because this coating solution is notalways sufficiently stable, the coating solution applied to thesubstrate came to gel in some cases during the coating operation,particularly a continuous operation by transfer printing, whereby thecontinuous operation intended met with difficulties. In additionthereto, the coating solution had to be kept at below 15° C. in order topreserve it for an extended period of time.

The present invention is intended to solve such problems associated withthe prior art as mentioned above. That is, firstly, an object of theinvention is to provide a coating solution (hereinafter called coatingsolution I) for forming transparent conductive ceramic coatings, saidcoating solution being a homogeneous solution or dispersion of anacetylacetonate chelate compound and a conductive substance in a mixtureof water and an organic solvent.

Secondly, an object of the invention is to provide a coating solution(hereinafter called coating solution II) for forming transparentconductive ceramic coatings, said coating solution being a homogeneoussolution or dispersion of an acetylacetonate chelate compound (excludingdialkoxybisacetylacetonatozirconium), a silicon compound and aconductive substance in a mixture of water and an organic solvent.

Thirdly, an object of the invention is to provide a coating solution(hereinafter called coating solution III) for forming transparentconductive ceramic coatings, said coating solution being a homogeneoussolution or dispersion of an acetylacetonate chelate compound, alkoxideof metal other than silicon, and a conductive substance in a mixture ofwater and an organic solvent.

Fourthly, an object of the invention is to provide a coating solution(hereinafter called coating solution IV) for forming transparentconductive ceramic coatings, said coating solution being a homogeneoussolution or dispersion of an acetylacetonate chelate compound, a siliconcompound, alkoxide of metal other than silicon and a conductivesubstance in a mixture of water and an organic solvent.

Fifthly, an object of the invention is to provide a substrate(hereinafter called substrate A), such as composed of glass, plastics orthe like, on which transparent conductive ceramic coatings being formedby using the coating solution I, II, III or IV, said conductive ceramiccoatings being excellent in durability, transparency, resistance toscuffing, adhesion and antistatic effect, and sixthly an object of theinvention is to provide a substrate (hereinafter called substrate B) onwhich transparent conductive ceramic coatings having anti-glare inaddition to those performance characteristics as mentioned above, andfurther to provide processes for preparing such substrates as mentionedabove.

Seventhly, an object of the invention is to provide a displaying device(hereinafter called displaying device A) comprising the substrate A as aface-plate.

Eighthly, an object of the invention is to provide a displaying device(hereinafter called displaying device B) comprising the substrate B as aface-plate.

Ninthly, an object of the invention is to provide a copy machinecomprising the substrate A as a platen glass.

DISCLOSURE OF THE INVENTION

The coating solution I of the present invention is characterized bycomprising a homogeneous solution or dispersion of an acetylacetonatechelate compound and a conductive substance in a mixture of water and anorganic solvent.

The coating solution II of the present invention is characterized bycomprising a homogeneous solution or dispersion of an acetylacetonatechelate compound (excluding dialkoxy-bisacetonato zirconium), a siliconcompound and a conductive substance in a mixture of water and an organicsolvent.

The coating solution III of the present invention is characterized bycomprising a homogeneous solution or dispersion of an acetylacetonatechelate compound, alkoxide of metal other than silicon, and a conductivesubstance in a mixture of water and an organic solvent.

The coating solution IV of the present invention is characterized bycomprising a homogeneous solution or dispersion of an acetylacetonatechelate compound, a silicon compound, alkoxide of metal other thansilicon, and a conductive substance in a mixture of water and an organicsolvent.

The substrate A of the present invention is characterized by comprisinga substrate and thereon a transparent conductive ceramic coating formedby using the above-mentioned coating solution I, II, III or IV, andhaving a surface resistance of 10³ -10¹¹ Ω/□, a total lighttransmittance of at least 85% and a haze of less than 10%.

The substrate B of the present invention is characterized by comprisinga substrate and thereon a transparent conductive ceramic coating formedby using the above-mentioned coating solution I, II, III or IV, andhaving a surface resistance of 10³ -10¹¹ Ω/□ and a glossiness of30-100%.

The displaying device A of the present invention is characterized bycomprising as a face-plate the substrate A comprising a substrate andthereon a transparent conductive ceramic coating formed by using theabove-mentioned coating solution I, II, III or IV, said substrate Ahaving a surface resistance of 10³ -10¹¹ Ω/□, total light transmittanceof at least 85%, a haze of less than 10% and a resolving power of atleast 50 bars/cm.

The displaying device B of the present invention is characterized bycomprising as a face-plate the substrate B comprising a substrate andthereon a transparent conductive ceramic coating formed by using theabove-mentioned coating solution, I, II, III or IV, said substrate Bhaving a surface resistance of 10³ -10¹¹ Ω/□, a glossiness of 30-100%and a resolving power of at least 50 bars/cm.

The copy machine of the present invention is characterized by having asa platen glass the substrate A comprising a substrate and thereon atransparent conductive ceramic coating formed by using theabove-mentioned coating solution I, II, III or IV, said substrate Ahaving a surface resistance of 10³ -10¹¹ Ω/□, a total lighttransmittance of at least 85% and a haze of less than 10%.

The first process preferred in the present invention for preparing asubstrate with a transparent conductive ceramic coating of the inventionis characterized by coating the substrate preheated to 40°-90° C. withthe above-mentioned coating solution I, II, III or IV, followed bydrying and/or heating.

The second process particularly preferred in the present invention forpreparing a substrate with a transparent conductive ceramic coating ofthe invention is characterized by coating the substrate with theabove-mentioned coating solution I, II, III or IV, and irradiating thecoating as formed with an electromagnetic wave having a wavelengthshorter than that of visible light after and/or during at least one ofthe steps of applying the coating solution, on the substrate, drying thecoating as formed on the substrate and heating the dried coating.

The third process particularly preferred in the present invention forpreparing a substrate with a transparent conductive ceramic coating ofthe invention is characterized by (1) coating the substrate with atransparent conductive ceramic coating as obtained above on the surfacethereof with a coating solution for forming a transparent protectivecoating, followed by drying and/or heating, or (2) keeping the substratewith a transparent conductive ceramic coating as obtained above at40°-90° C. by preheating, and coating the preheated substrate on thesurface thereof with a coating solution for forming a transparentprotective coating, followed by drying and/or heating.

The fourth process particularly preferred in the present invention forpreparing a substrate with a transparent conductive ceramic coating ofthe invention is characterized by repeating the above-mentioned thirdprocess of the invention except that the transparent protective coatingformed on the substrate is irradiated with an electromagnetic wavehaving a wavelength shorter than that of visible light after and/orduring at least one of the steps of applying the coating solution forforming a transparent protective coating on the substrate, drying thetransparent protective coating as formed on the substrate and heatingthe dried transparent protective coating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique view of a copy machine equipped with an automaticdocument feeder.

FIG. 2 is a view illustrating a bar chart used in the determination ofresolving power of substrate.

FIG. 3 is a view illustrating a device used in the determination ofresolving power of substrate.

1 . . . Copy machine

2 . . . Automatic feeder

3 . . . Platen glass

4 . . . Bar chart

BEST MODE FOR PRACTICING THE INVENTION

Hereinafter, the coating solution I of the present invention is firstillustrated in detail.

The coating solution I of the present invention is formed byhomogeneously dissolving or dispersing an acetylacetonate chelatecompound and a conductive substance in a mixture of water and an organicsolvent. The components of this coating solution are illustrated below.

As used herein, the term acetylacetonate chelate compound is intended toinclude chelate compounds having acetylacetone molecule as a ligand, andthe chelate compounds are those represented by the following formula (I)or condensates thereof. In the present invention, there may be used oneor a combination of two or more selected from among the chelatecompounds or condensates thereof as mentioned above. In the coatingsolution I, it is presumed that the acetylacetonate chelate compoundplays a role in improvement of dispersibility of the conductivesubstance and thermal stability of the coating solution, and functionsas a protective colloid for the conductive substance. ##STR1## whereina+b is equal to 2-4, a is 0-3, b is 1-4, R is --C_(n) H_(2n+1) (n=3 or4), X is CH₃ --, CH₃ O--, C₂ H₅ -- or C₂ H₅ O--, and M₁ is an elementselected from among those belonging to Groups IB, IIA, B, IIIA, B, IVA,B, VA, B, VIA, VIIA and VIII in the periodic table or vanadyl (VO). Inthe above formula (I), preferred combinations of these elements or VOwith a and b are as shown in the following table.

    ______________________________________                                        a       0-1           0-2       0-3                                           b       1-2           1-3       1-4                                           a + b   2             3         4                                             M.sub.1 Co, Cu, Mg,   Al, Cr, Fe,                                                                             Ti, Zr, Hf,                                           Mn, Pb, Ni,   V, Co, In,                                                                              Sb                                                    Zn, Sn, Ba,   Ta, Y, B                                                        Be, Vo                                                                ______________________________________                                    

The conductive substance used in the present invention includes thosehitherto known as conductive substances such as tin oxide, tin oxidedoped with antimony, fluorine or phosphorus, indium oxide, or indiumoxide doped with tin or fluorine.

These conductive substances are desirably in the form of finely dividedparticle having an average particle diameter of less than 0.4 μm. Forapplications in face-plates of displaying devices such as CRT, FIP, PDPand LCD or in platen glass of copy machine where high transparent withlow haze is required, it is preferable to use the conductive substanceshaving an average particle diameter of 0.01-0.1 μm. In this case,however, it is desirable that at least 60% of the total particle of theconductive substance used is occupied by particles having a particlediameter of less than 0.1 μm, because the resulting transparentconductive ceramic coating comes to decrease in transparency if theconductive substance used contains increased amounts of particles havinga particle diameter exceeding 0.1 μm even when said conductive substanceused have an average particle diameter of less than 0.1 μm.

Such conductive substances as illustrated above are described in detailin Japanese Patent L-O-P Publn. No. 11519/1988 "Process for preparingconductive powder" and Japanese Patent L-O-P Publn. No. 230617/1987 "Tinoxide sol and process for preparing same", both applied by the presentapplicant.

The organic solvent used in the present invention includes alcohols suchas methanol, ethanol, propanol, butanol, diacetone alcohol, furfurylalcohol, ethylene glycol and hexylene glycol, esters such as methylacetate and ethyl acetate, ethers such as diethyl ether, ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonobutyl ether, diethylene glycol monomethyl ether and diethyleneglycol monoethyl ether, and ketones such as acetone and methyl ethylketone, which may be used either singly or in combination.

In the coating solution I composed of the above-mentioned components, aweight ratio of the conductive substance to the acetylacetonate chelatecompound in terms of oxide thereof is preferably 0.5=EO_(x) /M₁ O_(x) =5(EO_(x) represents the conductive substance as oxide, and M₁ O_(x)represents the acetylacetonate chelate compound as oxide). If a value ofthis ratio is less than 0.5, conductivity of the resulting coating isnot sufficient and, on the other hand, if this value exceeds 5, theresulting coating becomes poor in transparency, adhesion and resistanceto scuffing, and the coating solution tends to become poor inpreservability and continuous productivity.

A solids concentration calculated as (EO_(x) +M₁ O_(x)) in the coatingsolution I of the invention may be less than 15% by weight. If thisvalue exceeds 15% by weight, the coating solution tends to become poorin preservability and, on the other hand, if the above-mentioned solidsconcentration is excessively low, several times of coating operation arerequired for obtaining a desired film thickness of the coating obtainedthereby, and hence the solids concentration of at least 0.1% by weightis practically useful.

A water concentration in the coating solution I of the invention ispreferably 0.1-50% by weight. If this value is less than 0.1% by weight,the acetylacetonate chelate compound present in the coating solution isnot sufficiently hydrolyzed and unaltered product of the acetylacetonatechelate compound remains in the coating resulted therefrom, wherebyadhesion between the resultant coating and a substrate comes todeteriorate. Further, the coating obtained tends to decrease inresistance to scuffing and durability. On the other hand, if this valueexceeds 50% by weight, repulsion between the coating solution and thesubstrate takes place at the time of coating said coating solution onsaid substrate, whereby the formation of a coating becomes difficult.

The coating solution II of the present invention is formed byhomogeneously dissolving or dispersing an acetylacetonate chelatecompound (excluding dialkoxy-bisacetylacetonatozirconium), a siliconcompound and a conductive substance in a mixture of water and an organicsolvent.

The coating solution III of the present invention is formed byhomogeneously dissolving or dispersing an acetylacetonate chelatecompound, alkoxide of metal other than silicon, and a conductivesubstance in a mixture of water and an organic solvent.

Further, the coating solution IV of the present invention is formed byhomogeneously dissolving or dispersing an acetylacetonate chelatecompound, a silicon compound, alkoxide of metal other than silicon, anda conductive substance in a mixture of water and an organic solvent.

In the coating solutions II, III and IV of the invention mentionedabove, the acetylacetonate chelate compound, conductive substance andmixture of water and an organic solvent used are the same as those usedin the coating solution I of the invention. On that account, the siliconcompound and alkoxide of metal other than silicon are illustratedhereinafter.

In this connection, the acetylacetonate chelate compound used in thesecoating solutions includes all the compounds represented by theaforementioned formula (I). However, the compound of the formula (I) inwhich M₁ is Zr, a is 2 and b is 2 corresponds todialkoxy-bisacetylacetonatozirconium which has already been claimed in aseparate patent application as filed previously by the presentapplicant. For this reason, in the coating solution II, thisdialkoxy-bisacetylacetonatozirconium is excluded from the scope of theacetylacetonate chelate compound used in said coating solution.

In the coating solutions II, III and IV, it is presumed that theacetylacetonate chelate compound plays a role in improvement ofdispersibility of the conductive substance and thermal stability of thecoating solution, and functions as a protective colloid for theconductive substance.

The silicon compound used includes one or a combination of two or moreselected from among the compounds represented by the following formula(II) or condensates thereof.

    R.sub.a --Si(OR').sub.4-a                                  (II)

wherein R is C_(n) H_(2n+1) -- (n=1-4), hydrogen or halogen atom, a is0-3, and R' is C_(n) H_(2n+1) -- (n=1-4), hydrogen atom or C_(n)H_(2n+1) OC₂ H₄ -- (n=1-4).

These silicon compounds may be used, as they are, or may be used afterhaving been partially hydrolyzed. The silicon compounds may be partiallyhydrolyzed, for example, by the general procedure for partial hydrolysisof silicon compound which comprises mixing the silicon compound withmethanol or ethanol and adding water and acid to the resulting mixture,thereby effecting partial hydrolysis. However, this partial hydrolysisis desirably carried out especially under such conditions as thosementioned below. The acid used includes hydrochloric acid, nitric acid,phosphoric acid, acetic acid or acetic anhydride, and the proportion ofthe acid to the silicon compound is preferably 0.01≦acid/SiO₂ ≦0.5 (aweight ratio when the silicon compound is expressed in terms of SiO₂).If this value is less than 0.01, a large amount of unaltered siliconcompound remains, whereby the resulting coating tends to decrease inconductivity. On the other hand, if this value exceeds 0.5, the rate ofpartial hydrolysis becomes excessively fast, whereby continuousproductivity and preservability of the coating solution tend todecrease. The proportion of water to the silicon compound is preferablywater/the silicon compound ≦2 (a molar ratio when the silicon compoundis expressed in terms of SiO₂). If this value is less than 2, because ofunaltered silicon compound remaining in the resulting coating, adhesionbetween the coating as formed and the substrate decreases, whereby thecoating formed tends to decrease in resistance to scuffing anddurability. The temperature at which the partial hydrolysis is carriedout is desirably 30°-80° C.

The alkoxide of metal other than silicon used includes one or acombination of two or more selected from among compounds represented bythe formula M₂ (OR)_(n) wherein M₂ is a metal other than silicon, R isalkyl or C_(n) H_(2n) O-- (n=3-10), and n is an integer equal to avalency of M₂, or condensates thereof. M₂ in the above formula may be ofany metal other than silicon, and is preferably a metal selected fromamong elements belonging to Groups IB, IIA, B, IIIA, B, IVA, B, VA, B,VIA, B and VIII in the periodic table, especially from among Cu, Be, Ba,Zn, Al, B, In, Ga, Ti, Zr, Hf, Ge, Sn, Pb, V, Nb, Ta, Bi, Sb, Cr, W, Fe,Ni, Sc, Y, Ce and Te. Vanadyl (VO) is also preferably usable and definedas a metal other than silicon.

These alkoxides other than silicon alkoxide may be used, as they are,without subjecting to partial hydrolysis.

In the coating solutions II, III and IV composed of the above-mentionedcomponents, the proportion of the acetylacetonate chelate compound tothe conductive substance is preferably 0.001≦M₁ O_(x) /EO_(x) ≦1 (aweight ratio in terms of oxide thereof). If this value is less than0.001, the conductive substance decreases in dispersibility and thecoating solution decreases in thermal stability, whereby the coating asformed tends to become poor in transparency and adhesion to thesubstrate and the coating solution tends to become poor inpreservability and continuous productivity. On the other hand, if thisvalue exceeds 1, the coating obtained tends to become poor intransparency and adhesion to the substrate or decrease in conductivity.

The proportion of the acetylacetonate chelate compound to the siliconcompounds and/or alkoxide of metal other than silicon in terms of oxidethereof is preferably 0.001≦M₁ O_(x) /A≦10, wherein M₁ O_(x) is a weightof the acetylacetonate chelate compound in terms of oxide thereof, A isSiO₂ in the case of the coating solution II, is M₂ O_(x) in the case ofthe coating solution II, and is SiO₂ +M₂ O_(x) in the case of thecoating solution IV, provided that M₂ O_(x) is to represents alkoxide ofmetal other than silicon in terms of oxide thereof. If this value isless than 0.001, alkali resistance, acid resistance, resistance tosaline solution and solvent resistance of the coating formed are notsatisfactory and, on the other hand, if this value exceeds 10, thecoating obtained tends to decrease in adhesion to the substrate andtransparency.

In the coating solution IV, the proportion of the silicon compound toalkoxide of metal other than silicon is preferably 0.001≦M₂ O_(x) /(M₂O_(x) +SiO₂)≦0.99 (a weight ratio).

A proportion of the conductive substance in terms of oxide thereof ispreferably 0.5≦EO_(x) /(A+M₁ O_(x))≦5 (weight ratio). If this value isless than 0.5, conductivity of the coating formed is not satisfactoryand, on the other hand, if this value exceeds 5, the coating formedtends to decrease in adhesion to the substrate and resistance toscuffing.

The solids concentration in the coating solutions II, III and IV shouldbe less than 15% by weight calculated as EO_(x) +A+M₁ O_(x). If thisvalue exceeds 15% by weight, the coating solution tends to become poorin preservability and, on the other hand, if the above-mentioned solidsconcentration is excessively low, it becomes necessary to repeat severaltimes the coating operation and hence a practically useful solidsconcentration is at least 0.1% by weight.

The water concentration in the coating solutions II, III and IV ispreferably 0.1-50% by weight. If this value is less than 0.1% by weight,partial hydrolysis among the acetylacetonate chelate compound, siliconcompound and alkoxide of metal other than silicon is not sufficientlycarried out, whereby adhesion between the coating and substratedecreases or the coating obtained tends to decrease in resistance toscuffing and durability. On the other hand, if this value exceeds 50% byweight, repulsion between the coating solution and substrate takes placeat the time of applying said coating solution on said substrate, wherebythe formation of a coating becomes difficult.

Hereinafter, the processes for preparing the coating solutions I, II,III and IV are illustrated. The coating solution I may be prepared bymixing together the conductive substance, water, an organic solvent andthe acetylacetonate chelate compound according to any method suitabletherefor. The coating solutions II, III and IV may be prepared by addingat least one acetylacetonate chelate compound to a dispersion of theconductive substance in water and an organic solvent to improve saidconductive substance in dispersibility and stability, and then addingthereto the silicon compound and/or alkoxide of metal other thansilicon. Alternatively, these coating solutions II, III and IV may alsobe prepared by previously mixing the acetylacetonate chelate compoundwith the silicon compound and/or alkoxide of metal other than silicon,and then mixing the resultant mixture with the conductive substance. Inthese cases, contact of the silicon compound and/or alkoxide of metalother than silicon with the conductive substance before the addition ofthe acetylacetonate chelate compound is undesirable, because theconductive substance in contact therewith will agglomerate.

In the coating solutions I, II, III and IV of the present invention thusprepared, the conductive substance present in the coating solution is ina monodispersed state by the protective colloidal action of theacetylacetonate chelate compound, and accordingly coatings excellent intransparency and conductivity can be obtained therefrom. Because ofimproved thermal stability, moreover, these coating solutions do not gelat the time of continuous coating operation, and can be preserved for along period of time even at a temperature of about 40° C.

In the present invention, there may be used transparent substratescomposed of glass or plastics to which the above-mentioned coatingsolution I, II, III or IV is applied, and these substrates may be of anyshape such as flat plate or plate with a curved surface. Substrateshaving a toughened surface, for example, ground glass, may also be usedin the invention. This is because, when the coating solution is appliedto the surface of the substrate with a toughened surface, the appliedcoating solution cover evenly the roughened surface of said substrate,whereby the covered surface becomes flat and the substrate becomestransparent. When the substrates with a roughened surface is used,adhesion between the coating and substrate is markedly improved.

Hereinafter, the substrate A is illustrated.

The substrate A comprises a substrate and thereon a transparentconductive ceramic coating formed from the above-mentioned coatingsolution I, II, III or IV, and has a surface resistance of 10³ -10¹¹Ω/□, a total light transmittance of at least 85% and a haze of less than10%.

The substrate A may be prepared by coating the above-mentioned substratewith the aforementioned coating solution I, II, III or IV according tosuch coating method as dipping, spinner, spray, roll coater orflexographic printing to form a flat wet coating on the substrate,followed by drying and/or heating. After coating, the flat wet coatingis dried at a temperature of from room temperature to about 110° C.,whereby the substrate A having the coating and excellent in adhesion tothe substrate, resistance to scuffing and transparency. When this driedcoating is further heated at a temperature of above 120° C. and belowthe glass transition point of the substrate, the substrate A improvedfurther in durability is obtained. In this case, the heating may berepeated any times at a temperature so long as the temperature is belowthe glass transition point of the substrate.

In the present invention, the substrate A having further remarkableeffects is obtained when it is prepared by the processes as will bementioned hereinafter.

Of the processes as referred to above, the first process for preparingthe substrate A comprises irradiating the substrate with anelectromagnetic wave having a wavelength shorter than that of visiblelight after and/or during at least one of the steps (1) of coating thesubstrate with the coating solution, (2) of drying the coating formed onsaid substrate and (3) of heating the dried coating. By virtue ofirradiation of the coating with the electromagnetic wave, a lowerheating temperature of the coating can be employed. For example, acoating obtained by irradiation with the above-mentioned electromagneticwave followed by heating at a temperature of 300° C. is found to beequal in performance characteristics to a coating obtained by heating ata temperature of 400° C. without irradiation with the electromagneticwave.

The electromagnetic wave having a wavelength shorter than that ofvisible light as referred to above includes ultraviolet rays, electronrays, X-rays, γ-rays and the like, and among these rays, ultravioletrays are practically useful. As a source of ultraviolet rays, there maybe used desirably a high pressure mercury-vapor lamp having an emissionmaximum at about 250 nm and 360 nm and an irradiation intensity of atleast 10 mW/cm², preferably 100 mW/cm². A high durability coating isobtained at low temperatures when the coating is irradiated withirradiation energy of at least 100 mJ/cm², preferably at least 1000mJ/cm² using such a source of ultraviolet rays as mentioned above.

In the second process for preparing the substrate A, the surface of thecoating formed on the substrate A obtained in the manner as mentionedabove is further coated with a coating solution for forming atransparent protective coating according to such coating method asdipping, spinner, spray, roll coater, flexographic printing or the like,followed by drying and/or heating. The coating solution for forming atransparent protective coating used in this case may be of any coatingsolution so long as it gives a transparent protective coating consistingessentially of SiO₂ and/or ZrO₂. For example, useful coating solutionsinclude those containing partial hydrolyzate of alkoxide of silicon orzirconium, a chelate compound of silicon or zirconium, oxysalt ofzirconium and the like. The coating solution I, II, III or IV of thepresent invention, from which the conductive substance has beenexcluded, may also be used.

In the third process for preparing the substrate A, the transparentprotective coating obtained in the manner as the above-mentioned secondprocess is irradiated with an electromagnetic wave having a wavelengthshorter than that of visible light after and/or during at least one ofthe steps (1) of applying the coating solution for forming a transparentprotecting coating, (2) of drying the transparent protective coating asformed and (3) of heating the dried transparent protective coating.

The substrate A thus prepared has a surface resistance of 10³ -10¹¹ Ω/□,a total light transmittance of at least 85% and a haze of less than 10%.If the surface resistance of the substrate A exceeds 10¹¹ Ω/□, nosufficient antistatic effect is obtained. If the total lighttransmission and haze fail to satisfy their respective numerical valuesas defined above, the substrate A becomes poor in transparency.

In the displaying device A having as a face-plate the substrate A of thepresent invention, the substrate A as the face-plate desirably has aresolving power of at least 50 bars/cm in addition to its performancecharacteristics mentioned above. This resolving power is determined bythe following procedure. That is, a bar chart 4 as shown in FIG. 2 isattached to a side 7 having no coating of the substrate A, and thissubstrate A is arranged in a box 9 of 50 cm in width and 30 cm in lengthso that the coated side of the substrate A is exposed outside the box 9in the manner as shown in FIG. 3 to ascertain how many bars separatedper cm can visually be confirmed at a distance of 30 cm from thesubstrate A. The number of bars separated per cm that can visually beconfirmed was taken as a resolving power of the substrate A. In thiscase, the inner walls of the box 9 were colored white, and fluorescentlamps 8 of 20 W were provided on both sides of the inner wall of the box9 opposite to the substrate A. The bar chart used included thoseprepared by increasing the number of bars every 5 bars/cm, for example,those having 10 bars/cm, 15 bars/cm, 20 bars/cm, 25 bars/cm and thelike. In the bar chart, 5 is a printed bar portion, 6 is a space betweenthe bars, and a width a of the printed portion is equal to a width b ofthe space.

In the copy machine using the substrate A of the present invention as aplaten glass, said substrate A desirably has a light transmittance at awavelength of 550 nm which does not exceed ±5% based on the lighttransmittance of the substrate A as measured before forming a coatingthereon.

The coating formed on this substrate A is composed of ceramics and verydifficult to scrape off, however, a kind of flaw is left on the coatingwhen part of said coating is scraped off by the document to be fed toADF or by a rubber belt fitted to ADF, and becomes thinner or thesubstrate before coating is exposed.

When a difference in light transmittance at a wavelength of 550 nmbetween the flaw portion of the coating and the substrate before coatingexceeds +5%, this flaw portion appears as a spot on the copies obtainedby operating at a gray scale a copy machine having such substrate A asmentioned above as a platen glass.

Accordingly, in the case where the substrate A is used as a platen glassof copy machine, when values of light transmittance at a wavelength of550 nm of the substrate A, the flaw portion and the substrate A beforecoating are taken as Tt₁ (%), Tt₂ (%) and Tt₀ (%), respectively, it isdesirable that both Tt₁ -Tt₀ and Tt₂ -Tt₀ do not exceed ±5%, preferably±3%.

In the present invention, when the substrate A is used as a platen glassof copy machine, a substrate used, on which the coating of the substrateA is formed, may be of any substrate for platen glass used in copymachine.

Hereinafter, the substrate B of the present invention is illustrated.

The substrate B comprises a substrate and thereon a transparentconductive ceramic coating formed from the above-mentioned coatingsolution I, II, III or IV, and has a surface resistance of 10³ -10¹¹ Ω/□and a glossiness of 30-100%.

In the first process for preparing the substrate B mentioned above, theabove-mentioned coating solution I, II, III or IV is applied to thesurface of a substrate preheated at 40°-90° C., preferably 50°-70° C. toform an uneven wet coating on the substrate, followed by drying and/orheating.

When the substrate is kept by preheating at a temperature below 40° C.in that case, the coating solution being applied is not sufficientlydried and undergoes leveling, whereby a flat wet coating is formed andtends to fail of its being anti-glare. On the other hand, if thesubstrate is kept at a temperature exceeding 90° C., the coatingsolution applied to the substrate is abruptly dried, whereby the driedcoating tends to decrease in adhesion to the substrate, transparency anddurability. At the time when the substrate is coated with the coatingsolution in the manner as mentioned above, it is desirable to controlthe amount of coating solution and coating speed so that the temperatureat which the substrate is kept by preheating does not deviate from thetemperature range as defined above. After coating, the coating formed isdried at a temperature of from ordinary temperature to about 110° C. toobtain the substrate B having formed thereon a dry coating excellent inadhesion to the substrate, resistance to scuffing and transparency. Thisdry coating as formed is further heated at a temperature above 120° C.and below the glass transition point of the substrate, to obtain thesubstrate B having a heated film improved in durability. In this case,the dry coating formed on the substrate by the previous step may beheated repeatedly at a temperature below the glass transition point ofthe substrate.

In the second process for preparing the substrate B, said process beingthe same as the above-mentioned first process for preparing thesubstrate B, the coating to be formed is irradiated with anelectromagnetic wave having a wavelength shorter than that of visiblelight after and/or during at least one of the steps (1) of applying thecoating solution on the substrate, (2) of drying the wet coating asformed and (3) of heating the dried coating. By virtue of theirradiation with the electromagnetic wave as mentioned above, a lowerheating temperature can be employed. For example, a coating obtained byirradiation with the electromagnetic wave followed by heating at atemperature of 300° C. is found to be equal in performancecharacteristics to a coating obtained by heating at a temperature of400° C. without irradiation with the electromagnetic wave.

In the third process for preparing the substrate B, the aforementionedsubstrate A having no transparent protective coating formed thereon andthe substrates B obtained by the above-mentioned first and secondprocesses, respectively, were kept by further preheating at 40°-90° C.,and coated with a coating solution for forming a transparent protectivecoating to form an uneven wet coating, followed by drying and/orheating. The coating solution for forming a transparent protectivecoating used in that case may be the same as used in the second processfor preparing the substrate A.

In the fourth process for preparing the substrate B, said process beingthe same as the above-mentioned third process for preparing thesubstrate B, the transparent protective coating to be formed isirradiated with an electromagnetic wave having a wavelength shorter thanthat of visible light after and/or during at least one of the steps (1)of applying the coating solution for forming a transparent protectivecoating on the substrate B, (2) of drying the transparent protectivecoating as formed and (3) of heating the dried transparent protectivecoating.

The electromagnetic wave having a wavelength shorter than that ofvisible light used in the second and fourth processes for preparing thesubstrate B is the same as that used in the processes for preparing thesubstrate A.

In the processes for preparing the substrate B, the coating solution isdesirably coated on the substrate by the spray method.

The substrate B obtained in the manner as mentioned above has a surfaceresistance of 10³ -10¹¹ Ω/□ and a glossiness of 30-100% as measured atan angle of 60° according to the method of measurement of glossiness asstipulated in JIS K7105-81.

In the displaying device B using the substrate B of the presentinvention as a face-plate, the substrate B as a face-plate desirably hasa resolving power of at least 50 bars/cm in addition to theaforementioned performance characteristics. This resolving power ismeasured by the same procedure as employed in the substrate A used as aface-plate.

The glossiness of the substrate B is a value as measured at an angle of60° according to the method of measurement of glossiness stipulated inJIS K7105-81 as aforesaid. If this value is less than 30%, the substrateB tends to decrease in transparency and, on the other hand, if thisvalue, though its upper limit is not particularly defined, exceeds 100%,the substrate will not come to be anti-glare, and said value isdesirably less than 100%.

The substrate B desirably has an average surface roughness R_(z) (aten-point average roughness as measured in accordance with JIS B0601-82)of 0.2-5.0 μm. If this average roughness is less than 0.2 μm, thesubstrate B, though excellent in resolving power and transparency,decreases in anti-glare characteristics and tends to fail to obtainsufficient antistatic effect and, on the other hand, if said averageroughness exceeds 5.0 μm, the substrate B tends to decrease in resolvingpower and transparency.

EFFECT OF THE INVENTION

The coating solution of the present invention is formed by homogeneouslydissolving or dispersing an acetylacetonate chelate compound and aconductive substance as aforesaid in a mixture of water and an organicsolvent, or by homogeneously dissolving or dispersing an acetylacetonatechelate compound, a silicon compound and/or alkoxide of metal other thansilicon, and a conductive substance in a mixture of water and an organicsolvent.

Accordingly, the coating solutions of the present invention are capableof forming a coating excellent in transparency and conductivity, becausethe conductive substance present in the coating solution is kept in amonodispersed state by the protective colloidal action of theacetylacetonate chelate compound. Because of improved thermal stability,the coating solutions will not undergo gellation at the time ofcontinuous coating operation thereof, and can be preserved for a longperiod of time even at a temperature of about 40° C.

The substrates A and B of the present invention having on the substratethereof a coating composed of a metal oxide such as zirconia or silicaand a conductive substance are excellent in resistance to scuffing,adhesion to the substrate and durability.

The substrate A of the present invention has a surface resistance of 10³-10¹¹ Ω/□, a total light transmittance of at least 85% and a haze ofless than 10%, and the substrate B of the invention has a surfaceresistance of 10³ -10¹¹ Ω/□ and a glossiness of 30-100% as measured atan angle of 60° according to the method of measurement of glossiness asstipulated in JIS K7105-81, thus both substrates A and B are excellentin transparency, antistatic effect and anti-glare.

In the displaying device A having the substrate A of the presentinvention as a face-plate, a resolving power of the substrate A as aface-plate is at least 50 bars/cm, and in the displaying device B havingthe substrate B as a face-plate, a resolving power of the substrate B asa face-plate is at least 50 bars/cm.

In the copy machine using the substrate A of the invention as a platenglass, because a light transmittance at a wavelength of 550 nm of thesubstrate A as a platen glass does not exceeds ±5% of a lighttransmittance of the substrate prior to coating, even when part of thecoating becomes thinner by scraping or part of the coating is completelyscraped off, the scraped portion of the coating will not appear as aspot on the copy resulting from the copy machine operated at a grayscale.

Accordingly, the substrates with a transparent conductive ceramiccoating of the present invention can be applied to the field whereinantistatic function and anti-glare are required, for example, aface-plate of displaying device such as CRT, FIP, PDP or LCD, a platenglass of copy machine, a panel for measuring instrument, telewritingterminal and lens.

This face-plate may be such as constituting the displaying deviceitself, or may be arranged in front of the displaying device.Concretely, in the case of LCD, the transparent conductive ceramiccoating may be formed directly on the surface of one of the substrateswith electrodes holding the liquid crystal therebetween and positionedin front of LCD, or the substrate having formed thereon the transparentconductive ceramic coating of the invention may be arranged in front ofthe substrate with an electrode on front side. In the case of CRT, thetransparent conductive ceramic coating of the present invention may beformed directly on a displaying panel of CRT, or the substrate havingformed thereon the transparent conductive ceramic coating may bearranged in front of the displaying panel.

The present invention is illustrated below with reference to examples,but it should be construed that the invention is in no way limited tothose examples.

EXAMPLES 1˜6

Coating solution I

Coating solutions for forming transparent conductive ceramic coatings(coating solutions 1-6) as shown in Table 1 were obtained by stirringmixtures comprising the following acetylacetonate chelate compounds,conductive substances and organic solvents.

Acetylacetonate chelate compound (M₁ O_(x))

(1) ZABI

A butanol solution containing 15% by weight ofdibutoxy-bisacetylacetonatozirconium in terms of ZrO₂.

(2) TAPI

A butanol solution containing 10% by weight ofdibutoxy-bisacetylacetonatotitanium in terms of TiO₂.

Conductive substance (EO_(x))

(1) TL93

Tin oxide sol doped with antimony (a product sold under the trade nameof ELCOM TL-93 by Shokubai Kasei Kogyo K.K., solids concentration 20% byweight, average particle diameter 0.07 μm, particles of lees than 1 μmamounting to 87% of the total particle)

(2) TL30

A water dispersion of particulate tin oxide doped with antimony (aproduct sold under the trade name of ELCOM TL-30 by Shokubai Kasei KogyoK.K., solids concentration 20% by weight, average particle diameter 0.2μm)

Organic Solvent

Ethanol (EtOH) and isopropanol (IPA)

                  TABLE 1                                                         ______________________________________                                                                        Organic                                       Example M.sub.1 O.sub.x                                                                           EO.sub.x    solvent                                       No.             g             g           g                                   ______________________________________                                        1       ZAB1    100     TL93   65   EtOH  355                                 2       ZAB1    100     TL93  130   EtOH  550                                 3       ZAB1    100     TL93  325   EtOH  1135                                4       ZAB1    100     TL93   65   EtOH   95                                 5       TAP1    100     TL93   50   IPA   250                                 6       TAP1    100     TL30  100   IPA   800                                 ______________________________________                                    

EXAMPLES 7˜21

Coating solution II Coating solutions for forming transparent conductiveceramic coatings (coating solutions 7-21) as shown in Table 3 wereobtained by mixing together the following acetylacetonate chelatecompounds, conductive substances and organic solvents, followed byadding the following silicon liquids.

Acetylacetonate chelate compound (M₁ O_(x))

(1) ZABI (same as used in Examples 1-6)

(2) ZAB2

A butanol solution containing 10% by weight of Zr(OC₄ H₉)₁.5.(Ac)₂.5(Ac: acetylacetone ion) in terms of ZrO₂.

(3) ZAB3

A butanol solution containing 10% by weight oftributoxy-monoacetylacetonatozirconium in terms of ZrO₂.

(4) TAPI (same as used in Examples 1-6)

(5) TAP2

An IPA solution containing 10% by weight of triisopropoxymonoacetylacetonatotitanium in terms of TiO₂.

(6) HFAB

A butanol solution containing 10% by weight ofdibutoxy-bisacetylacetonatohafnium in terms of HfO₂.

Conductive substance

(1) TL93 and TL30 (same as used in Examples 1-6)

(2) TL130

A water dispersion of particulate indium oxide doped with tin (a productsold under the trade name of ELCOM TL-130 by Shokubai Kasei Kogyo K.K.,solids concentration 25% by weight, average particle diameter 0.25 μm)

Silicon liquid

(1) Silicon liquids A-D, and F

An ethanol solution containing 28% by weight of tetraethoxysilane interms of SiO₂ (ethyl silicate 28, a product of Tama Kagaku Kogyo K.K.,called ES-28 for short) or an ethanol solution containing 40% by weightof tetraethoxysilane in terms of SiO₂ (a product of the same company asmentioned above, called ES-40 for short) were respectively incorporatedwith ethanol and further with an aqueous solution of nitric acid. Thesemixtures obtained were individually heated for a predetermined period oftime and then cooled to room temperature to obtain the title siliconliquids as shown in Table 2.

(2) Silicon liquid E

1000 g of an aqueous solution of sodium silicate (SiO₂ /Na₂ O=3 mol/mol)containing 5% by weight of SiO₂ was kept at 15° C. and passed, as itwas, through a cation exchange resin column. To this solution was added445 g of methyl cellosolve, and the mixture was thoroughly dispersed.The mixture was then heated at 70° C. by means of a rotary evaporator todistilled off 945 g of water under reduced pressure, whereby the siliconliquid E was obtained.

                  TABLE 2                                                         ______________________________________                                               SiO.sub.2   solvent   Nitric  Heating                                  Silicon                                                                              source      (ETOH)    acid    conditions                               liquid         g       g       Wt % g    °C.                                                                         h                               ______________________________________                                        A      ES-28   416     484     4.0  300  50   1.0                             B      ES-40   74.4    144.6   11.1 81   50   1.0                             C      ES-40   74.4    135.6   0.4  90   60   0.5                             D      ES-40   744     2100    2.0  600  60   0.5                             F      ES-40   74.4    147.6   4.4  78   40   2.0                             ______________________________________                                    

                                      TABLE 3                                     __________________________________________________________________________                         Organic Silicon                                          M.sub.1 O.sub.x                                                                            EO.sub.x                                                                              solvent liquid                                                     g      g       g       g                                            __________________________________________________________________________    Example 7                                                                           ZAB2                                                                              100                                                                              TL93                                                                              550 EtOH                                                                              2750                                                                              A   1000                                         Example 8                                                                           ZAB2                                                                              100                                                                              TL93                                                                              300 EtOH                                                                               300                                                                              B   200                                          Example 9                                                                           ZAB2                                                                              100                                                                              TL93                                                                              225 EtOH                                                                               900                                                                              C   125                                          Example 10                                                                          ZAB2                                                                              100                                                                              TL93                                                                              550 EtOH                                                                              2750                                                                              D + E                                                                             1000                                         Example 11                                                                          ZAB3                                                                              100                                                                              TL130                                                                             550 IPA 2400                                                                              F   300                                          Example 12                                                                          TAP1                                                                              100                                                                              TL93                                                                              4330                                                                              EtOH                                                                              17528                                                                             A   3330                                               ZAB1                                                                              692                                                                 Example 13                                                                          TAP1                                                                              100                                                                              TL93                                                                              6675                                                                              IPA 88296                                                                             A   1670                                               ZAB1                                                                              692                                                                 Example 14                                                                          TAP1                                                                              100                                                                              TL93                                                                              133 MeBu                                                                               160                                                                              B   140                                                ZAB1                                                                               19                                                                 Example 15                                                                          TAP2                                                                              100                                                                              TL30                                                                              900 EtOH                                                                              6523                                                                              B   400                                                ZAB1                                                                               77                                                                 Example 16                                                                          ZAB3                                                                              100                                                                              TL93                                                                              4330                                                                              EtOH                                                                              17528                                                                             A   3330                                               ZAB1                                                                              692                                                                 Example 17                                                                          HFAB                                                                               10                                                                              TL93                                                                              210 EtOH                                                                               840                                                                              A   200                                          Example 18                                                                          HFAB                                                                               10                                                                              TL93                                                                              165 EtOH                                                                              1925                                                                              A   100                                          Example 19                                                                          TAP1                                                                              100                                                                              TL93                                                                              563 IPA  563                                                                              B   125                                          Example 20                                                                          TAP1                                                                              100                                                                              TL93                                                                              215 IPA 1075                                                                              B   330                                          Example 21                                                                          ZAB2                                                                               1 TL93                                                                              1000                                                                              EtOH                                                                              5169                                                                              B   1000                                         __________________________________________________________________________     Note 1)                                                                       The silicon liquid used in Example 10 is a mixture of 500 g each of D and     E liquids.                                                                    Note 2)                                                                       The organic solvent used in Example 14 is a mixed solvent of methanol and     butanol (weight ratio 1/1).                                              

EXAMPLES 22˜26

Coating solution III

Coating solutions for forming transparent conductive ceramic coatings(coating solutions 22-26) as shown in Table 4 were obtained by mixingtogether the following acetylacetonate chelate compound, conductivesubstance and organic solvents, followed by adding the following metalalkoxides.

Acetylacetonate chelate compound

(1) AAC

A solution of 5% by weight of trisacetylacetonatoaluminum in terms ofAl₂ O₃ in an ethanol/toluene mixed solvent (weight ratio 1/1).

Conductive substance

(1) TL94

Tin oxide sol doped with phosphorus (a product sold under the trade nameELCOM TL-94 by Shokubai Kasei Kogyo K.K., solids concentration 20% byweight, average particle diameter 0.07 μm, particles of less than 0.1 μmamounting to 87% of the total particle)

Metal alkoxide (M₂ O_(x))

(1) TBZR

A butanol solution containing 10% by weight of tetrabutoxy zirconium interms of ZrO₂.

(2) TPTI

An IPA solution containing 10% by weight of tetraisopropoxy titanium interms of TiO₂.

                                      TABLE 4                                     __________________________________________________________________________    Example                                                                            M.sub.1 O.sub.x                                                                             EO.sub.x                                                                              Organic                                            No.      g  M.sub.2 O.sub.x                                                                          g   solvent                                            __________________________________________________________________________    22   AAC 100                                                                              TBZR                                                                               63                                                                              TL94                                                                              169.5                                                                             EtOH 571.5                                         23   ZAB3                                                                              100                                                                              TPTI                                                                              200                                                                              TL93                                                                              300 EtOH 525                                           24   ZAB3                                                                              100                                                                              TPTI                                                                              100                                                                              TL93                                                                              275 MeBu 1815                                          25   ZAB3                                                                              100                                                                              TPTI                                                                              100                                                                               TL130                                                                            130 Me-cello                                                                           130                                           26   ZAB3                                                                               1 TBZR                                                                              1000                                                                             TL93                                                                              500 EtOH 5169                                          __________________________________________________________________________     Note)                                                                         Mecello is methyl cellosolve                                             

EXAMPLES 27-32

Coating solution IV

Coating solutions for forming transparent conductive ceramic coatings(coating solutions 27-32) as shown in Table 5 were obtained by mixingtogether the following acetylacetonate chelate compounds, conductivesubstances and organic solvents, followed by addition to the mixture ofsilicon liquids and metal alkoxides.

Acetylacetonate chelate compound

(1) COA

A solution of 10% by weight of bisacetylacetonatocobalt in terms of CoOin a toluene/acetone mixed solvent (weight ratio 1/1)

Metal alkoxide

(1) PETA

An ethanol solution containing 5% by weight of pentaethoxy tantalum interms of Ta₂ O₅.

The coating solution 30 of Example 30 was prepared by the followingprocedure.

A mixture comprising predetermined amounts of TAPI, TL30 and ethanol wasprepared. Separately, a mixture comprising 250 g of an IPA solution(TMS) containing 10% by weight of monomethyl trimethoxysilane in termsof SiO₂, 250 g of TPTI, 2.5 g of acetic anhydride and 60 g of water wasprepared. This mixture was added to the above-mentioned mixture, and theresulting mixture was thoroughly stirred to obtain the coating solution30.

                                      TABLE 5                                     __________________________________________________________________________                       Silicon       Organic                                      Example                                                                            M.sub.1 O.sub.x                                                                      M.sub.2 O.sub.x                                                                      liquid EO.sub.x                                                                             Solvent                                      No.      g      g     g       g      g                                        __________________________________________________________________________    27   ZAB3                                                                              10 TBZR                                                                              20 A  80  TL93                                                                              110                                                                              EtOH                                                                              400                                      28   ZAB3                                                                              100                                                                              TBZR                                                                              83 B  83  TL93                                                                              400                                                                              EtOH                                                                              667                                      29   ZAB3                                                                              10 TBZR                                                                              90 B  10  TL93                                                                              220                                                                              EtOH                                                                              220                                      30   TAP1                                                                              100                                                                              TPTI                                                                              250                                                                              TMS                                                                              250 TL30                                                                              300                                                                              EtOH                                                                              3037.5                                   31   COA 10 PETA                                                                              40 A  80  TL94                                                                              110                                                                              MeBu                                                                              420                                      32   ZAB3                                                                               1 TBRZ                                                                               1 B  1000                                                                              TL93                                                                              500                                                                              EtOH                                                                              5171                                     __________________________________________________________________________

EXAMPLES 33-1˜33-32

Coatings were formed respectively on panel glasses for 14-inchcathode-ray tube by coating said panel glasses with the coatingsolutions for forming transparent conductive ceramic coatings obtainedin Examples 1-32 under the conditions as shown in Table 6. The panelglasses thus coated were evaluated item-by-item by the followingprocedures.

Results obtained are shown in Tables 7 and 8, respectively.

(1) Transparency:

Total light transmittance (Tt) at a Wavelength of 550 nm, and haze (H)were measured by means of a haze computer (manufactured by Suga ShikenkiK.K.)

(2) Surface resistance (Rs):

Surface resistance (Rs) was measured by means of Hiresta (voltageapplied: 500 V) or Loresta (voltage applied: 10-90 V) manufactured byMitsubishi Yuka K.K.).

(3) Resolving power:

A bar chart as shown in FIG. 2 is attached to a side having no coatingof the substrate, and this substrate is arranged in a box in such amanner as shown in FIG. 3 so that the coated side of the substrate isexposed outside the box. The number of bars separated per cm that can bevisually confirmed was taken as a resolving power of the substrate. Inthis case, the bar chart used included those prepared by increasing thenumber of bars every 5 bar/cm, for example, those having 10, 15, 20 and25 bar/cm.

(4) Glossiness (G):

Glossiness (G) was measured at an angle of 60° according to the methodof measurement of glossiness as stipulated in JIS K7105-81. In thiscase, the back of the substrate to be measured was colored black orpasted with a black tape in order to avert the influence of reflectedlight therefrom.

(5) Adhesion:

A part of a commercially available adhesive cellophane tape of a 12 mmwidth was applied to the coating, the remainder of the tape was heldperpendicular to the coating, and the tape was abruptly peeled offtherefrom to visually inspect the coating remaining on the panel glass.

(6) Film strength:

The panel glass was fixed onto a platform scale, an eraser for office(equivalent to LION No. 50--50) was put on the coating on said panelglass, and the eraser was reciprocated 150 times under a load of 2 kg torub the surface of the coating, and then a surface resistance (Rs) andglossiness (G) of the thus rubbed panel glass were measured.

(7) Average roughness (Rz):

Average roughness (Rs) was determined in accordance with the method ofmeasurement of Rz as stipulated in JIS B0601-82 using a film thicknessmeter (sold under the trade name of Taly Step by Rank Tylor Hobson Co.).

(8) Durability:

The coated panel glass was immersed in the following seven kinds ofliquids to evaluate adhesion between the coating and the panel glass.The glossiness and surface resistance of the coated panel glass measuredbefore the durability test were compared with those measured after thetest.

1) Immersion for 120 hours at room temperature in 15% by weight ofaqueous ammonia.

2) Immersion for 120 hours at room temperature in 10% by weight ofaqueous NaCl solution.

3) Immersion for 30 minutes in boiling water.

4) Immersion for 120 hours at room temperature in 50% by weight ofaqueous acetic acid solution.

5) Immersion for 1 week at room temperature in acetone.

6) Immersion for 1 week at room temperature in ethanol.

7) Immersion for 1 week at room temperature in n-propanol.

                                      TABLE 6                                     __________________________________________________________________________                  Pre-           UV            Pre-           UV                        Coating                                                                           Coating                                                                           heating                                                                          Drying                                                                              Heating                                                                             irradi-                                                                           Protective                                                                          Coating                                                                           heating                                                                          Drying                                                                              Heating                                                                             irradi-             Example                                                                             solution                                                                          method                                                                            °C.                                                                       °C.                                                                       min.                                                                             °C.                                                                       min.                                                                             ation                                                                             solution                                                                            method                                                                            °C.                                                                       °C.                                                                       min.                                                                             °C.                                                                       min.                                                                             ation               __________________________________________________________________________    33-1   1  SP  60 120                                                                              5  250                                                                              30 --  --    --  -- -- -- -- -- --                  33-2   2  SP  60 120                                                                              5  200                                                                              30 (1) --    --  -- -- -- -- -- --                  33-3   3  SP  70 120                                                                              5  -- -- --  A     SP  60 120                                                                              5  150                                                                              30 --                  33-4   4  SN  -- 120                                                                              5  300                                                                              30 --  --    --  -- -- -- -- -- --                  33-5   5  SP  60 120                                                                              5  -- -- --  B     SP  70 120                                                                              5  200                                                                              30 (1)                 33-6   6  SN  -- 120                                                                              5  -- -- --  C     SN  -- 120                                                                              5  150                                                                              30 --                  33-7   7  SN  -- 120                                                                              5  200                                                                              30 (1) --    --  -- -- -- -- -- --                  33-8   8  SN  -- 120                                                                              5  -- -- --  F     SN  -- 120                                                                              5  200                                                                              30 (1)                 33-9   9  SN  -- 120                                                                              5  -- -- --  D     SP  60 120                                                                              5  200                                                                              30 --                  33-10 10  SN  -- 120                                                                              5  -- -- (1) A     SP  60 120                                                                              5  150                                                                              30 (1)                 33-11 11  SP  80 120                                                                              5  -- -- (1) B     SP  50 120                                                                              5  200                                                                              30 (1)                 33-12 12  SP  60 120                                                                              5  -- -- (1) --    --  -- -- -- -- -- --                  33-13 13  SP  80 120                                                                              5  -- -- --  E     SP  70 120                                                                              5  180                                                                              30 (2)                 33-14 14  SN  -- 120                                                                              5  -- -- (1) --    --  -- -- -- -- -- --                  33-15 15  SN  -- 120                                                                              5  -- -- --  A     SN  -- 120                                                                              5  250                                                                              30 (2)                 33-16 16  SN  -- 120                                                                              5  -- -- --  B     SP  80 120                                                                              5  150                                                                              30 (2)                 33-17 17  SP  70 120                                                                              5  200                                                                              30 --  C     SP  60 120                                                                              5  150                                                                              30 --                  33-18 18  SP  60 120                                                                              5  150                                                                              30 (1) D     SP  60 120                                                                              5  150                                                                              30 (1)                 33-19 19  SN  -- 120                                                                              5  250                                                                              30 --  A     SN  -- 120                                                                              5  200                                                                              30 --                  33-20 20  SN  -- 120                                                                              5  200                                                                              30 --  A     SP  80 120                                                                              5  200                                                                              30 --                  33-21 21  SP  60 120                                                                              5  200                                                                              30 --  --    --  -- -- -- -- -- --                  33-22 22  SN  -- 120                                                                              5  200                                                                              30 (1) A     SN  -- 120                                                                              5  200                                                                              30 (1)                 33-23 23  SN  -- 120                                                                              5  150                                                                              30 (2) C     SP  60 120                                                                              5  150                                                                              30 (1)                 33-24 24  SP  90 120                                                                              5  250                                                                              30 --  C     SP  50 120                                                                              5  200                                                                              30 (2)                 33-25 25  SN  -- 120                                                                              5  200                                                                              30 --  B     SN  -- 120                                                                              5  180                                                                              30 (2)                 33-26 26  SP  60 120                                                                              5  200                                                                              30 --  --    --  -- -- -- -- -- --                  33-27 27  SP  80 120                                                                              5  170                                                                              30 --  --    --  -- -- -- -- -- --                  33-28 28  SN  --  90                                                                              5  400                                                                              30 --  --    --  -- -- -- -- -- --                  33-29 29  SN  -- 120                                                                              5  400                                                                              30 (1) --    --  -- -- -- -- -- --                  33-30 30  SP  60 120                                                                              5  150                                                                              30 --  A     SP  60 120                                                                              5  350                                                                              30 --                  33-31 31  SP  60 120                                                                              5  200                                                                              30 (1) B     SP  60 120                                                                              5  200                                                                              30 (1)                 33-32 32  SP  60 120                                                                              5  200                                                                              30 --  --    --  -- -- -- -- -- --                  __________________________________________________________________________     (1) After drying                                                              (2) After heating                                                             SP: Spray, Conditions: Feeding air pressure of spray = 2 kg/cm.sup.2,         Coating volume = 20 ml.                                                       SN: Spinner, Conditions: 1000 r.p.m.,                                         UV irradiation condition: 210 mW/cm.sup.2, irradiation for 3 minutes with     2 kW high pressure mercuryvapor lamp.                                    

                                      TABLE 7                                     __________________________________________________________________________                                 Film                                                       Resolving          strength                                              Tt H power G  Rs        Rs   G  Rz                                       Example                                                                            %  % bar/cm                                                                              %  Ω/                                                                           Adhesion                                                                           Ω/                                                                           %  μm                                    __________________________________________________________________________    33-1 91.5                                                                             --                                                                              65    65 5 × 10.sup.8                                                                 ◯                                                                      8 × 10.sup.8                                                                 70 1.02                                     33-2 90.5                                                                             --                                                                              65    63 1 × 10.sup.7                                                                 ◯                                                                      5 × 10.sup.7                                                                 66 1.05                                     33-3 92.3                                                                             --                                                                              70    62 1 × 10.sup.6                                                                 ◯                                                                      1 × 10.sup.6                                                                 65 0.98                                     33-4 91.2                                                                             0.6                                                                             70    148                                                                              2 × 10.sup.8                                                                 ◯                                                                      6 × 10.sup.8                                                                 144                                                                              0.02                                     33-5 91.9                                                                             --                                                                              75    68 5 × 10.sup.8                                                                 ◯                                                                      5 × 10.sup.8                                                                 69 1.12                                     33-6 92.1                                                                             3.5                                                                             60    130                                                                              3 × 10.sup.6                                                                 ◯                                                                      3 × 10.sup.6                                                                 140                                                                              0.08                                     33-7 91.4                                                                             1.6                                                                             70    151                                                                              1 × 10.sup.8                                                                 ◯                                                                      2 × 10.sup. 8                                                                149                                                                              0.03                                     33-8 92.3                                                                             0.3                                                                             75    145                                                                              7 × 10.sup.6                                                                 ◯                                                                      7 × 10.sup.6                                                                 145                                                                              0.01                                     33-9 92.4                                                                             --                                                                              70    65 7 × 10.sup.7                                                                 ◯                                                                      7 × 10.sup.7                                                                 69 0.89                                     33-10                                                                              92.8                                                                             --                                                                              75    67 3 × 10.sup.8                                                                 ◯                                                                      3 × 10.sup.8                                                                 66 0.74                                     33-11                                                                              92.4                                                                             --                                                                              55    35 5 × 10.sup.4                                                                 ◯                                                                      8 × 10.sup.4                                                                 42 1.45                                     33-12                                                                              91.5                                                                             --                                                                              70    66 7 × 10.sup.6                                                                 ◯                                                                      8 × 10.sup.6                                                                 68 0.94                                     33-13                                                                              92.2                                                                             --                                                                              75    54 5 × 10.sup.6                                                                 ◯                                                                      5 × 10.sup.6                                                                 53 1.05                                     33-14                                                                              91.0                                                                             0.8                                                                             70    153                                                                              9 × 10.sup.7                                                                 ◯                                                                      2 × 10.sup.8                                                                 150                                                                              0.02                                     33-15                                                                              92.4                                                                             1.5                                                                             60    132                                                                              1 × 10.sup.6                                                                 ◯                                                                      2 × 10.sup.6                                                                 136                                                                              0.07                                     33-16                                                                              91.9                                                                             --                                                                              70    62 6 × 10.sup.6                                                                 ◯                                                                      6 × 10.sup.6                                                                 64 0.83                                     33-17                                                                              92.1                                                                             --                                                                              75    53 8 × 10.sup.6                                                                 ◯                                                                      8 × 10.sup.6                                                                 51 1.10                                     33-18                                                                              92.0                                                                             --                                                                              75    55 2 × 10.sup.6                                                                 ◯                                                                      2 × 10.sup.6                                                                 54 0.84                                     33-19                                                                              91.9                                                                             0.4                                                                             75    158                                                                              8 × 10.sup.5                                                                 ◯                                                                      9 × 10.sup.5                                                                 155                                                                              0.01                                     33-20                                                                              92.4                                                                             --                                                                              70    65 3 × 10.sup.8                                                                 ◯                                                                      3 × 10.sup.8                                                                 62 0.96                                     33-21                                                                              91.8                                                                             --                                                                              65    55 8 × 10.sup.8                                                                 ◯                                                                      1 × 10.sup.8                                                                 61 0.58                                     33-22                                                                              93.1                                                                             0.2                                                                             75    158                                                                              2 × 10.sup.9                                                                 ◯                                                                      2 × 10.sup.9                                                                 157                                                                              0.01                                     33-23                                                                              91.8                                                                             --                                                                              70    64 7 × 10.sup.6                                                                 ◯                                                                      7 × 10.sup.6                                                                 63 0.93                                     33-24                                                                              92.7                                                                             --                                                                              70    46 9 × 10.sup.5                                                                 ◯                                                                      1 × 10.sup.6                                                                 47 1.15                                     33-25                                                                              91.8                                                                             0.8                                                                             65    135                                                                              1 × 10.sup.5                                                                 ◯                                                                      3 × 10.sup.5                                                                 140                                                                              0.04                                     33-26                                                                              90.1                                                                             --                                                                              60    51 7 × 10.sup.8                                                                 ◯                                                                      3 × 10.sup.9                                                                 59 0.72                                     33-27                                                                              90.3                                                                             --                                                                              65    63 2 × 10.sup.7                                                                 ◯                                                                      5 × 10.sup.7                                                                 68 0.95                                     33-28                                                                              90.1                                                                             0.5                                                                             70    158                                                                              2 × 10.sup.6                                                                 ◯                                                                      4 × 10.sup.6                                                                 153                                                                              0.02                                     33-29                                                                              91.1                                                                             0.9                                                                             70    161                                                                              8 × 10.sup.5                                                                 ◯                                                                      1 × 10.sup.5                                                                 156                                                                              0.02                                     33-30                                                                              92.3                                                                             --                                                                              55    35 7 × 10.sup.7                                                                 ◯                                                                      2 × 10.sup.8                                                                 44 1.33                                     33-31                                                                              93.9                                                                             --                                                                              70    49 6 × 10.sup.9                                                                 ◯                                                                      6 × 10.sup.9                                                                 49 1.23                                     33-32                                                                              91.5                                                                             --                                                                              65    59 1 × 10.sup.9                                                                 ◯                                                                      3 × 10.sup.9                                                                 65 0.47                                     __________________________________________________________________________

                                      TABLE 8                                     __________________________________________________________________________    Aqueous      NaCl    Boiling Acetic acid                                      ammonia      solution                                                                              water   solution                                                                              Acetone                                       Rs   G  Rs   G  Rs   G  Rs   G  Rs   G                                   Example                                                                            Ω/                                                                           %  Ω/                                                                           %  Ω/                                                                           %  Ω/                                                                           %  Ω/                                                                           %                                   __________________________________________________________________________    33-1 8 × 10.sup.8                                                                 69 6 × 10.sup.8                                                                 66 8 × 10.sup.8                                                                 68 6 × 10.sup.8                                                                 67 5 × 10.sup.8                                                                 65                                  33-2 4 × 10.sup.7                                                                 67 2 × 10.sup.7                                                                 65 5 × 10.sup.7                                                                 65 4 × 10.sup.7                                                                 64 1 × 10.sup.7                                                                 63                                  33-3 1 × 10.sup.6                                                                 64 1 × 10.sup.6                                                                 62 1 × 10.sup.6                                                                 63 1 × 10.sup.6                                                                 62 1 × 10.sup.6                                                                 62                                  33-4 5 × 10.sup.8                                                                 153                                                                              4 × 10.sup.8                                                                 150                                                                              5 × 10.sup.8                                                                 151                                                                              3 × 10.sup.8                                                                 150                                                                              2 × 10.sup.8                                                                 148                                 33-5 5 × 10.sup.8                                                                 68 5 × 10.sup.8                                                                 68 5 × 10.sup.8                                                                 68 5 × 10.sup.8                                                                 68 5 × 10.sup.8                                                                 68                                  33-6 3 × 10.sup.6                                                                 136                                                                              3 × 10.sup.6                                                                 138                                                                              3 × 10.sup.6                                                                 137                                                                              3 × 10.sup.6                                                                 134                                                                              3 × 10.sup.6                                                                 130                                 33-7 2 × 10.sup.8                                                                 154                                                                              2 × 10.sup.8                                                                 153                                                                              2 × 10.sup.8                                                                 153                                                                              1 × 10.sup.8                                                                 151                                                                              1 × 10.sup.8                                                                 151                                 33-8 7 × 10.sup.6                                                                 145                                                                              7 × 10.sup.6                                                                 145                                                                              7 × 10.sup.6                                                                 145                                                                              7 × 10.sup.6                                                                 145                                                                              7 × 10.sup.6                                                                 145                                 33-9 2 × 10.sup.7                                                                 68 1 × 10.sup.7                                                                 66 2 × 10.sup.7                                                                 68 1 × 10.sup.7                                                                 66 1 × 10.sup.7                                                                 65                                  33-10                                                                              3 × 10.sup.8                                                                 67 3 × 10.sup.8                                                                 67 3 × 10.sup.8                                                                 67 3 × 10.sup.8                                                                 67 3 × 10.sup.8                                                                 67                                  33-11                                                                              6 × 10.sup.4                                                                 38 5 × 10.sup.4                                                                 36 5 × 10.sup.6                                                                 38 5 × 10.sup.4                                                                 39 5 × 10.sup.4                                                                 35                                  33-12                                                                              8 × 10.sup.6                                                                 67 7 × 10.sup.6                                                                 66 8 × 10.sup.6                                                                 67 7 × 10.sup.6                                                                 66 7 × 10.sup.6                                                                 66                                  33-13                                                                              5 × 10.sup.6                                                                 54 5 × 10.sup.6                                                                 54 5 × 10.sup.6                                                                 54 5 × 10.sup.6                                                                 54 5 × 10.sup.6                                                                 54                                  33-14                                                                              1 × 10.sup.8                                                                 156                                                                              9 × 10.sup.7                                                                 155                                                                              9 × 10.sup.7                                                                 154                                                                              9 × 10.sup.7                                                                 153                                                                              9 × 10.sup.7                                                                 153                                 33-15                                                                              2 × 10.sup.6                                                                 135                                                                              1 × 10.sup.6                                                                 135                                                                              2 × 10.sup.6                                                                 136                                                                              1 × 10.sup.6                                                                 134                                                                              1 × 10.sup.6                                                                 132                                 33-16                                                                              6 × 10.sup.6                                                                 62 6 × 10.sup.6                                                                 62 6 × 10.sup.6                                                                 62 6 × 10.sup.6                                                                 62 6 ×  10.sup.6                                                                62                                  33-17                                                                              8 × 10.sup.6                                                                 55 8 × 10.sup.6                                                                 53 8 × 10.sup.6                                                                 54 8 × 10.sup.6                                                                 53 8 × 10.sup.6                                                                 53                                  33-18                                                                              2 × 10.sup.6                                                                 55 2 × 10.sup.6                                                                 55 2 × 10.sup.6                                                                 55 2 × 10.sup.6                                                                 55 2 × 10.sup.6                                                                 55                                  33-19                                                                              8 × 10.sup.5                                                                 160                                                                              8 × 10.sup.5                                                                 158                                                                              8 × 10.sup.5                                                                 156                                                                              8 × 10.sup.5                                                                 158                                                                              8 × 10.sup.5                                                                 158                                 33-20                                                                              4 × 10.sup.8                                                                 68 3 × 10.sup.8                                                                 66 3 × 10.sup.8                                                                 66 3 × 10.sup.8                                                                 65 3 × 10.sup.8                                                                 65                                  33-21                                                                              9 × 10.sup.8                                                                 53 8 × 10.sup.8                                                                 54 1 × 10.sup.9                                                                 52 8 × 10.sup.8                                                                 55 8 × 10.sup.8                                                                 54                                  33-22                                                                              2 × 10.sup.9                                                                 158                                                                              2 × 10.sup.9                                                                 158                                                                              2 × 10.sup.9                                                                 158                                                                              2 × 10.sup.9                                                                 158                                                                              2 × 10.sup.9                                                                 158                                 33-23                                                                              7 × 10.sup.6                                                                 64 7 × 10.sup.6                                                                 64 7 × 10.sup.6                                                                 64 7 × 10.sup.6                                                                 64 7 × 10.sup.6                                                                 64                                  33-24                                                                              9 × 10.sup.5                                                                 46 9 × 10.sup.5                                                                 46 9 × 10.sup.5                                                                 46 9 × 10.sup.5                                                                 46 9 × 10.sup.5                                                                 46                                  33-25                                                                              2 × 10.sup.5                                                                 137                                                                              2 × 10.sup.5                                                                 138                                                                              2 × 10.sup.5                                                                 139                                                                              3 × 10.sup.5                                                                 139                                                                              1 × 10.sup.5                                                                 135                                 33-26                                                                              7 × 10.sup.8                                                                 53 7 × 10.sup.8                                                                 52 8 × 10.sup.8                                                                 53 8 × 10.sup.8                                                                 51 7 × 10.sup.8                                                                 52                                  33-27                                                                              4 × 10.sup.7                                                                 67 4 × 10.sup.7                                                                 66 4 × 10.sup.7                                                                 66 3 × 10.sup.7                                                                 65 2 × 10.sup.7                                                                 63                                  33-28                                                                              3 × 10.sup.6                                                                 160                                                                              2 × 10.sup.6                                                                 159                                                                              3 × 10.sup.6                                                                 161                                                                              2 × 10.sup.6                                                                 158                                                                              2 × 10.sup.6                                                                 158                                 33-29                                                                              9 × 10.sup. 5                                                                162                                                                              8 × 10.sup.5                                                                 161                                                                              8 × 10.sup.5                                                                 161                                                                              8 × 10.sup.5                                                                 161                                                                              8 × 10.sup.5                                                                 161                                 33-30                                                                              1 × 10.sup.8                                                                 41 9 × 10.sup.8                                                                 39 1 × 10.sup.8                                                                 40 9 × 10.sup.7                                                                 38 7 × 10.sup.7                                                                 35                                  33-31                                                                              6 × 10.sup.9                                                                 49 6 × 10.sup.9                                                                 49 6 × 10.sup.9                                                                 49 6 × 10.sup.9                                                                 49 6 × 10.sup.9                                                                 49                                  33-32                                                                              3 × 10.sup.9                                                                 56 2 × 10.sup.9                                                                 57 2 × 10.sup.9                                                                 55 1 × 10.sup.9                                                                 59 2 × 10.sup.9                                                                 58                                  __________________________________________________________________________                                 EtOH    n-PrOH                                                                Rs   G  Rs   G                                                           Example                                                                            Ω/                                                                           %  Ω/                                                                           %                                   __________________________________________________________________________                            33-1 5 × 10.sup.8                                                                 65 5 × 10.sup.8                                                                 65                                                          33-2 1 × 10.sup.7                                                                 63 1 × 10.sup.7                                                                 63                                                          33-3 1 × 10.sup.6                                                                 62 1 × 10.sup.6                                                                 62                                                          33-4 2 × 10.sup.8                                                                 148                                                                              2 × 10.sup.8                                                                 148                                                         33-5 5 × 10.sup.8                                                                 68 5 × 10.sup.8                                                                 68                                                          33-6 3 × 10.sup.6                                                                 130                                                                              3 × 10.sup.6                                                                 130                                                         33-7 1 × 10.sup.8                                                                 151                                                                              1 × 10.sup.8                                                                 151                                                         33-8 7 × 10.sup.6                                                                 145                                                                              7 × 10.sup.6                                                                 145                                                         33-9 1 × 10.sup.7                                                                 65 1 × 10.sup.7                                                                 65                                                          33-10                                                                              3 × 10.sup.8                                                                 67 3 × 10.sup.8                                                                 67                                                          33-11                                                                              5 × 10.sup.4                                                                 35 5 × 10.sup.4                                                                 35                                                          33-12                                                                              7 × 10.sup.6                                                                 66 7 × 10.sup.6                                                                 66                                                          33-13                                                                              5 × 10.sup.6                                                                 54 5 × 10.sup.6                                                                 54                                                          33-14                                                                              9 × 10.sup.7                                                                 153                                                                              9 × 10.sup.7                                                                 153                                                         33-15                                                                              1 × 10.sup.6                                                                 132                                                                              1 × 10.sup.6                                                                 132                                                         33-16                                                                              6 × 10.sup.6                                                                 62 6 × 10.sup.6                                                                 62                                                          33-17                                                                              8 × 10.sup.6                                                                 53 8 × 10.sup.6                                                                 53                                                          33-18                                                                              2 × 10.sup.6                                                                 55 2 × 10.sup.6                                                                 55                                                          33-19                                                                              8 × 10.sup.5                                                                 158                                                                              8 × 10.sup.5                                                                 158                                                         33-20                                                                              3 × 10.sup.8                                                                 65 3 × 10.sup.8                                                                 65                                                          33-21                                                                              8 × 10.sup.8                                                                 55 8 × 10.sup.8                                                                 55                                                          33-22                                                                              2 × 10.sup.9                                                                 158                                                                              2 × 10.sup.9                                                                 158                                                         33-23                                                                              7 × 10.sup.6                                                                 64 7 × 10.sup.6                                                                 64                                                          33-24                                                                              9 × 10.sup.5                                                                 46 9 × 10.sup.5                                                                 46                                                          33-25                                                                              1 × 10.sup.5                                                                 135                                                                              1 × 10.sup.5                                                                 135                                                         33-26                                                                              8 × 10.sup.8                                                                 51 8 × 10.sup.8                                                                 51                                                          33-27                                                                              2 × 10.sup.7                                                                 63 2 × 10.sup.7                                                                 63                                                          33-28                                                                              2 × 10.sup.6                                                                 158                                                                              2 × 10.sup.6                                                                 158                                                         33-29                                                                              8 × 10.sup.5                                                                 161                                                                              8 × 10.sup.5                                                                 161                                                         33-30                                                                              7 × 10.sup.7                                                                 35 7 × 10.sup.7                                                                 35                                                          33-31                                                                              6 × 10.sup.9                                                                 49 6 × 10.sup.9                                                                 49                                                          33-32                                                                              1 × 10.sup.9                                                                 59 1 × 10.sup.9                                                                 59                                  __________________________________________________________________________

EXAMPLES 34-1˜34-31

Platen glasses having coatings thereon were prepared by coating sodaglasses, 450×300×4 mm, for platen glasses with the coating solutions forforming transparent conductive ceramic coatings obtained in Examples1-31 under the conditions as shown in Table 9. The platen glass thusprepared were evaluated item-by-item by the following procedures inaddition to the aforementioned items (1) and (2).

(9) Paper-passing test:

The coated platen glass was incorporated into a copy machine equippedwith ADF, and copying papers of A4 size were fed to ADF to count thenumber of papers passed therethrough before paper clogging takes place.

(10) Spot test:

The number of copying papers of A4 size fed to ADF of a copy machineoperated at a gray scale before spot appeared on the duplicated copy.Further, light transmission (Tt) at 550 nm was measured at the time whenspot appeared on the duplicated copy. The duplicated copy on which nospot appeared was measured for Tt after the paper passing test. (9).

For comparison, the platen glass before forming the coating thereon andITO glass having formed thereon ITO film by the sputtering method wereindividually incorporated into a copy machine, and the same evaluationas above were conducted.

Results obtained are shown in Table 10.

                                      TABLE 9                                     __________________________________________________________________________                            UV                                                    Coating     Drying                                                                              Heating                                                                             irradi-                                                                           Protective                                                                          Drying                                                                              Heating                                                                             irradi-                         Example                                                                            Solution                                                                             °C.                                                                       Min.                                                                             °C.                                                                       Min.                                                                             ation                                                                             solution                                                                            °C.                                                                       Min.                                                                             °C.                                                                       Min.                                                                             ation                           __________________________________________________________________________    34-1 1      120                                                                              5  350                                                                              30 --  --    -- -- -- -- --                              34-2 2      120                                                                              5  200                                                                              30 (1) --    -- -- -- -- --                              34-3 3      120                                                                              5  -- -- --  G     120                                                                              5  250                                                                              30 --                              34-4 4      120                                                                              5  -- -- --  G     120                                                                              5  200                                                                              30 (1)                             34-5 5      120                                                                              5  200                                                                              30 --  G     110                                                                              5  350                                                                              30 --                              34-6 6      100                                                                              5  -- -- --  G     110                                                                              5  350                                                                              30 --                              34-7 7      120                                                                              5  250                                                                              30 (2) --    -- -- -- -- --                              34-8 8      120                                                                              5  -- -- --  G     120                                                                              5  200                                                                              30 (2)                             34-9 9      100                                                                              5  300                                                                              30 --  G     120                                                                              5  150                                                                              30 --                              34-10                                                                              10     120                                                                              5  350                                                                              30 (2) G     120                                                                              5  300                                                                              30 (1)                             34-11                                                                              11     120                                                                              5  350                                                                              30 --  G     120                                                                              5  300                                                                              30 (2)                             34-12                                                                              12      80                                                                              5  250                                                                              30 --  --    -- -- -- -- --                              34-13                                                                              13      90                                                                              5  250                                                                              30 --  G     100                                                                              5  250                                                                              30 --                              34-14                                                                              14     120                                                                              5  400                                                                              30 --  --    --    -- -- --                              34-15                                                                              15     120                                                                              5  -- -- --  G     120                                                                              5  400                                                                              30 --                              34-16                                                                              16     120                                                                              5  400                                                                              30 (1) --    -- -- -- -- --                              34-17                                                                              17     120                                                                              5  -- -- (1) G     120                                                                              5  150                                                                              30 (1)                             34-18                                                                              18     120                                                                              5  -- -- (1) G     120                                                                              5  250                                                                              30 (2)                             34-19                                                                              19     120                                                                              5  -- -- --  G     120                                                                              5  300                                                                              30 --                              34-20                                                                              20     120                                                                              5  180                                                                              30 --  --    -- -- -- -- --                              34-21                                                                              21     120                                                                              5  200                                                                              30 --  G     120                                                                              5  200                                                                              30 --                              34-22                                                                              22     120                                                                              5  200                                                                              30 --  G     120                                                                              5  250                                                                              30 (3)                             34-23                                                                              23     120                                                                              5  -- -- --  G     120                                                                              5  350                                                                              30 --                              34-24                                                                              24     120                                                                              5  300                                                                              30 (1) --    -- -- -- -- --                              34-25                                                                              25     120                                                                              5  -- -- (1) G     120                                                                              5  200                                                                              30 (1)                             34-27                                                                              27     120                                                                              5  250                                                                              30 --  G     120                                                                              5  250                                                                              30 --                              34-28                                                                              28     120                                                                              5  250                                                                              30 --  --    -- -- -- -- --                              34-29                                                                              29     120                                                                              5  -- -- --  G     120                                                                              5  120                                                                              30 (2)                             34-30                                                                              30     120                                                                              5  200                                                                              30 (3) G     120                                                                              5  150                                                                              30 --                              34-31                                                                              31     120                                                                              5  250                                                                              30 --  G     120                                                                              5  250                                                                              30 (1)                             __________________________________________________________________________     (1) After drying                                                              (2) After heating                                                             (3) During drying                                                             Coating method: Roll coater                                                   UV irradiation conditions:                                                    210 mW/cm.sup.2, irradiation for 3 minutes with 2 kW high pressure            mercuryvapor lamp                                                        

                  TABLE 10                                                        ______________________________________                                                          Paper-                                                                        passing                                                                              Spot test                                                    Tt     H      Rs      test   Spot   Tt                                Example (%)    (%)    (Ω/ )                                                                           (sheet)                                                                              (sheet)                                                                              (%)                               ______________________________________                                        34-1    90.6   1.6    1 × 10.sup.9                                                                    >200000                                                                              >200000                                                                              90.2                              34-2    90.1   1.5    5 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.5                              34-3    92.1   0.5    1 × 10.sup.7                                                                    >200000                                                                              >200000                                                                              88.9                              34-4    92.3   0.3    4 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.1                              34-5    91.9   0.3    9 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.3                              34-6    92.1   2.8    6 × 10.sup.6                                                                    >200000                                                                              >200000                                                                              90.6                              34-7    89.8   1.3    8 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              91.9                              34-8    91.5   0.6    5 × 10.sup.6                                                                    >200000                                                                              >200000                                                                              90.2                              34-9    92.6   0.6    8 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.5                              34-10   90.8   1.9    3 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              88.9                              34-11   90.1   2.1    2 × 10.sup.4                                                                    >200000                                                                              >200000                                                                              90.1                              34-12   91.6   1.8    3 ×  10.sup.7                                                                   >200000                                                                              >200000                                                                              90.3                              34-13   92.6   0.3    5 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.6                              34-14   90.2   1.8    7 × 10.sup.7                                                                    >200000                                                                              >200000                                                                              91.9                              34-15   91.3   2.9    1 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.2                              34-16   89.5   1.5    3 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.5                              34-17   90.7   0.5    1 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              88.9                              34-18   90.1   0.3    5 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.1                              34-19   92.6   0.2    2 × 10.sup.5                                                                    >200000                                                                              >200000                                                                              90.3                              34-20   91.2   1.9    3 × 10.sup.9                                                                    >200000                                                                              >200000                                                                              90.6                              34-21   92.5   0.3    3 × 10.sup.9                                                                    >200000                                                                              >200000                                                                              91.3                              34-22   91.4   0.3    2 × 10.sup.9                                                                    >200000                                                                              >200000                                                                              91.9                              34-23   92.8   0.4    5 × 10.sup.6                                                                    >200000                                                                              >200000                                                                              90.2                              34-24   89.3   1.3    2 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              90.5                              34-25   92.6   1.9    3 × 10.sup.4                                                                    >200000                                                                              >200000                                                                              88.9                              34-27   92.1   0.8    5 × 10.sup.7                                                                    >200000                                                                              >200000                                                                              90.1                              34-28   90.4   1.7    4 × 10.sup.6                                                                    >200000                                                                              > 200000                                                                             90.3                              34-29   91.9   0.3    1 × 10.sup.6                                                                    >200000                                                                              >200000                                                                              90.6                              34-30   92.1   0.4    8 × 10.sup.8                                                                    >200000                                                                              >200000                                                                              91.9                              34-31   93.1   0.8    3 × 10.sup.9                                                                    >200000                                                                              >200000                                                                              91.9                              Platen  90.8   1.0     1 × 10.sup.13                                                                     100 >200000                                                                              90.8                              glass                                                                         ITO glass                                                                             91.0   0.52   2 × 10.sup.3                                                                    >200000                                                                                60000                                                                              85.5                              ______________________________________                                    

What is claimed is:
 1. A coating solution for forming a transparentconductive ceramic coating, said coating solution being a homogeneoussolution or dispersion consisting essentially of at least one compoundselected from the group consisting of an acetylacetonate chelatecompound and condensate thereof, and an inorganic conductive compound ina mixture of water and an organic solvent, wherein the acetylacetonatechelate compound is represented by the following formula: ##STR2##wherein a+b is 2-4, a is 0-3, b is 1-4, R is C_(n) H_(2n+1) -- (n=3 or4), X is CH₃ --, CH₃ O--, C₂ H₅ --, or C₂ H₅ O--, and M₁ is an elementselected from Groups IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB, VIA,VIIA, or VIII or vanadyl (VO).
 2. A coating solution for forming atransparent conductive ceramic coating, said coating solution being ahomogeneous solution or dispersion consisting essentially of:at leastone compound selected from the group consisting of an acetylacetonatechelate compound and condensates thereof wherein said acetylacetonatechelate compound excludes dialkoxybisacetylacetonatozirconium; aninorganic conductive compound; and a hydrolyzable silicon compound; in amixture of water and an organic solvent, wherein the acetylacetonatecompound is represented by the following formula: ##STR3## wherein a+bis 2-4, a is 0-3, b is 1-4, R is C_(n) H_(2n+1) -- (n=3 or 4), X is CH₃--, CH₃ O--, C₂ H₅ --, or C₂ H₅ O--, and M₁ is an element selected fromGroups IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB, VIA, VIIA, or VIII orvanadyl (VO).
 3. A coating solution for forming a transparent conductiveceramic coating, said coating solution being a homogeneous solution ordispersion consisting essentially of:at least one compound selected fromthe group consisting of an acetylacetonate chelate compound andcondensates thereof; an inorganic conductive compound; and an alkoxideof metal other than silicon; in a mixture of water and an organicsolvent, wherein the acetylacetonate compound is represented by thefollowing formula: ##STR4## wherein a+b is 2-4, a is 0-3, b is 1-4, R isC_(n) H_(2n+1) -- (n=3 or 4), X is CH₃ --, CH₃ O--, C₂ H₅ --, or C₂ H₅O--, and M₁ is an element selected from Groups IB, IIA, IIB, IIIA, IIIB,IVA, IVB, VA, VB, VIA, VIIA, or VIII or vanadyl (VO).
 4. A coatingsolution for forming a transparent conductive ceramic coating, saidcoating solution being a homogeneous solution or dispersion consistingessentially of:at least one compound selected from the group consistingof an acetylacetonate chelate compound and condensates thereof; aninorganic conductive compound; a hydrolyzable silicon compound; and; analkoxide of metal other than silicon; in a mixture of water and anorganic solvent, wherein the acetylacetonate compound is represented bythe following formula: ##STR5## wherein a+b is 2-4, a is 0-3, b is 1-4,R is C_(n) H_(2n+1) -- (n=3 or 4), X is CH₃ --, CH₃ O--, C₂ H₅ --, or C₂H₅ O--, and M₁ is an element selected from Groups IB, IIA, IIB, IIIA,IIIB, IVA, IVB, VA, VB, VIA, VIIA, or VIII or vanadyl (VO).
 5. Thecoating solution of claim 2 or 4 wherein said hydrolyzable siliconcompound is at least one of the compounds selected from the groupconsisting of a hydrolyzable silicon compound represented by thefollowing formula (II):

    R.sub.a --Si(OR').sub.4-a                                  (II)

wherein R is C_(n) H_(2n+1) -- (n=1-4), hydrogen or halogen atom, R' isC_(n) H2n+1-- (n=1-4), hydrogen atom or C_(n) H_(2n+1) OC₂ H₄ --(n=1-4), and a is 0-3; and condensate thereof.
 6. The coating solutionof claim 3 or 4 wherein said alkoxide of metal other than silicon is atleast one of the compounds selected from the group consisting of analkoxide of metal other than silicon represented by the followingformula (III):

    M.sub.2 (OR).sub.n                                         (III)

wherein n is an integer equal to a valency of M₂, R is alkyl or C_(n)H_(2n) O-- (n=3-10), and M₂ is a metal other than silicon; andcondensate thereof.
 7. The coating solution of claim 1 wherein theinorganic conductive compound is tin oxide, tin oxide doped withantimony, fluorine or phosphorous, indium oxide, or indium oxide dopedwith tin or fluorine.
 8. The coating solution of claim 1, wherein theinorganic conductive compound is dispersed in said coating solution inthe form of particles having an average particle diameter of less than0.4 μm.
 9. The coating solution of claim 1, wherein the inorganicconductive compound is dispersed in said coating solution in the form ofparticles having an average particle diameter of 0.01 to 0.1 μm.
 10. Thecoating solution of claim 1, wherein a weight ratio of the inorganicconductive compound per the acetylacetonate chelate compound in terms ofoxide thereof is from 0.5 to 5, a solids concentration of the inorganicconductive compound and the acetylacetonate chelate compound in terms ofoxide thereof is from 0.1% to 15% by weight, and the water concentrationin the coating solution is from 0.1 to 50% by weight.
 11. The coatingsolution as claimed in claim 2, 3 or 4, wherein a weight ratio of theacetylacetonate chelate compound per the inorganic conductive compoundin terms of oxide thereof is from 0.001 to 1 and the water concentrationin the coating solution is from 0.1 to 50% by weight.
 12. The coatingsolution of claim 2, wherein a weight ratio of the acetylacetonatechelate compound per the hydrolyzable silicon compound in terms of oxidethereof is from 0.001 to 10, a weight ratio of the inorganic conductivecompound per total amount of the acetylacetonate chelate compound andthe hydrolyzable silicon compound in terms of oxide thereof is from 0.5to 5 and a solids concentration of the inorganic conductive compound,the acetylacetonate chelate compound and the hydrolyzable siliconcompound in terms of oxide thereof is from 0.1% to 15% by weight. 13.The coating solution of claim 3, wherein a weight ratio of theacetylacetonate chelate compound per the alkoxide of metal other thansilicon in terms of oxide thereof is from 0.001 to 10, a weight ratio ofthe inorganic conductive compound per total amount of theacetylacetonate chelate compound and the alkoxide of metal other thansilicon in terms of oxide thereof is from 0.5 to 5 and a solidsconcentration of the inorganic conductive compound, the acetylacetonatechelate compound and the alkoxide of metal other than silicon in termsof oxide thereof is from 0.1% to 15% by weight.
 14. The coating solutionof claim 4, wherein a weight ratio of the acetylacetonate chelatecompound per total amount of the hydrolyzable silicon compound and thealkoxide of metal other than silicon in terms of oxide thereof is from0.001 to 10, a weight ratio of the inorganic conductive compound pertotal amount of the acetylacetonate chelate compound, the hydrolyzablesilicon compound and the alkoxide of metal other than silicon in termsof oxide thereof is from 0.5 to 5, a weight ratio of the alkoxide ofmetal other than silicon per total amount of the hydrolyzable siliconcompound and the alkoxide of metal other than silicon in terms of oxidethereof is from 0.001 to 0.99 and a solids concentration of theinorganic conductive compound, the acetylacetonate chelate compound, thehydrolyzable silicon compound and the alkoxide of metal other thansilicon in terms of oxide thereof is from 0.1% to 15% by weight.
 15. Acoating solution for forming a transparent conductive ceramic coating,said coating solution being a homogeneous solution or dispersioncomprising:at least one compound selected from the group consisting ofan acetylacetonate chelate compound and condensates thereof; aninorganic conductive compound; in a mixture of water and an organicsolvent, wherein the acetylacetonate compound is represented by thefollowing formula: ##STR6## wherein a+b is 2-4, a is 0-3, b is 1-4, R isC_(n) H_(2n+1) -- (n=3 or 4), X is CH₃ --, CH₃ O, C₂ H₅ --, or C₂ H₅O--, and M₁ is an element selected from Groups IB, IIA, IIB, IIIA, IIIB,IVA, IVB, VA, VB, VIA, VIIA, or VIII or vanadyl (VO).
 16. The coatingsolution of claim 15 wherein said acetylacetonate chelate compoundexcludes dialkoxybisacetylacetonatozirconium, and wherein said coatingsolution further comprises a hydrolyzable silicon compound.
 17. Thecoating solution of claim 15 further comprising an alkoxide of metalother than silicon.
 18. The coating solution of claim 15 furthercomprising a hydrolyzable silicon compound and an alkoxide of metalother than silicon.
 19. The coating solution of claim 16 or 18 whereinsaid hydrolyzable silicon compound is at least one of the compoundsselected from the group consisting of a hydrolyzable silicon compoundrepresented by the following formula (II):

    R.sub.a --Si(OR').sub.4-a                                  (II)

wherein R is C_(n) H_(2n+1) -- (n=l-4), hydrogen or halogen atom, R' isC_(n) H_(2n+1) -- (n=1-4), hydrogen atom or C_(n) H_(2n+1) OC₂ H₄ --(n=1-4), and a is 0-3; and condensate thereof.
 20. The coating solutionof claim 17 or 18 wherein said alkoxide of metal other than silicon isat least one of the compounds selected from the group consisting of analkoxide of metal other than silicon represented by the followingformula (III):

    M.sub.2 (OR).sub.n                                         (III)

wherein n is an integer equal to a valency of M₂, R is alkyl or C_(n)H_(2n) O-- (n=3-10), and M₂ is a metal other than silicon; andcondensate thereof.
 21. The coating solution of claim 15 wherein theinorganic conductive compound is tin oxide, tin oxide doped withantimony, fluorine or phosphorous, indium oxide, or indium oxide dopedwith tin or fluorine.